The invention relates to an electronic control apparatus for a fuel injection system having a timing device for the generation of electrical injection pulses whose duration is dependent on operating characteristics. One such known control apparatus has an apparatus for limiting the maximum duration of injection pulses, whereby this limiting value is furnished parallel to each injection pulse.
However, when operating internal combustion engines with injection systems, it has proved to be desirable not only to fix the maximum injection duration but also, when needed, to limit the variation of the duration of injection from pulse to pulse. This continuous monitoring of the time differential in the duration of two injection pulses which occur in series is not possible in the control apparatus embodied in accordance with the prior art.